title: Synthesis of mono- and 1,3-diaminocalix[4]arenes via Ullmann-type amination and amidation of 1,3-bistriflate esters of calix[4]arenes.
abstract: Practical methods are described for the preparation of monoamines 4 and 1,3-diamines 5, bearing one or two amino group(s) instead of the hydroxy group(s) at the 28-position or at both the 26- and 28-positions of p-tert-butylcalix[4]arene (1a) and p-tert-butylthiacalix[4]arene (1b), via the Ullmann-type amination or amidation. Thus, the copper-catalyzed or mediated amination of the 1,3-bistriflate ester (2a) of 1a with benzylamine affords either mono(benzylamino) triflate 7a or 1,3-bis(benzylamine) 8 in a high yield, depending on the reaction conditions. On the other hand, the 1,3-bistriflate ester (2b) of 1b resists disubstitution and produces, under stoichiometric conditions, mono(benzylamino) triflate 7b. The disubstitution of 2b is achieved by amidation with tosylamide, giving 1,3-bis(tosylamide) 17b. The hydrogenolysis of the benzylamino moiety of 7a, followed by the hydrolysis of the Tf moiety, affords monoamine 4a, while the hydrogenolysis of 8 affords 1,3-diamine 5a. The amino moiety of 7b can be deprotected under acidic conditions to give, after hydrolysis, monoamine 4b. The hydrolysis of 17b affords 1,3-diamine 5b. The overall yields of compounds 4a, 4b, 5a, and 5b are 72%, 45%, 78%, and 24%, respectively, based on commercially available compounds 1 and are much higher than the ones previously reported in the literature.
authors.affiliation: Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, 6-6-11 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Shinya
authors.initials: S
authors.lastname: Tanaka
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Serizawa
authors.forename: Naoya
authors.initials: N
authors.lastname: Morohashi
authors.forename: Tetsutaro
authors.initials: T
authors.lastname: Hattori
mesh_terms: D000586:Amination; D047250:Calixarenes / Q000138:chemical synthesis* / Q000737:chemistry; D003959:Diamines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008698:Mesylates / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D003959:Diamines; D008698:Mesylates; D047250:Calixarenes